Thousands of balloon fly into the sky above Yerba Buena after being released, Wednesday March 2, 2011, to promote the new game, "HomeFront', in San Francisco, Calif.Thousands of balloon fly into the sky above Yerba Buena after being released, Wednesday March 2, 2011, to promote the new game, "HomeFront', in San Francisco, Calif.

Photo: Lacy Atkins, The Chronicle

Thousands of balloon fly into the sky above Yerba Buena after being...

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Approximately 10,000 red balloons were released March 2, 2011, during a promotional event sponsored by game publisher THQ during which they had people rally to demonstrate against the North Korean regime and the treatment of its citizens. They launched upwards of 10,000 balloons to simulate a method used by South Korea to send messages of hope to the North. THQ sponsored this event in conjunction with the upcoming release of their video game Homefront, which depicts a speculatively fictional future based on the North Korean civil rights movement. The balloons are floating into Pier 14 in this photograph.

Photo: Mathew Grimm, Special To The Chronicle

Approximately 10,000 red balloons were released March 2, 2011,...

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Some of the thousands of balloon that were released to promote the new game Homefront, didn't get off the ground, Wednesday March 2, 2011, in San Francisco, Calif.

A publicity stunt for a new warfare-based video game sent local environmentalists to arms when a mass of balloons carrying advertisements for the game cascaded into San Francisco Bay.

"When I looked out the window and saw thousands of balloons dropping straight into the bay, I was flabbergasted," said Rod Fujita, a senior oceans scientist for the Environmental Defense Fund. "I never expected to see something like this in San Francisco, where there's such concern about the bay and pollution."

The release of the 10,000 ill-fated red balloons came courtesy of THQ, a Southern California video game company in town for the Game Developers Conference at Moscone Center.

Because the game is set in a near-future where the United States is invaded by nuclear-armed troops from North Korea, the company staged a mock lunchtime rally at Yerba Buena Gardens where the game's supporters, in the words of the company's news release, "will take to the streets to demonstrate against the North Korean regime and the treatment of its citizens."

The staged rally was capped by the massive balloon launch, designed, the company said, to "simulate a method used by South Korea to send messages of hope to the North."

The "messages of hope" carried by these balloons, however, amounted to an exclusive offer from GameStop video game store allowing gamers to "receive the resistance multi-player pack, featuring an exclusive weapon."

Even that message didn't get too far. While the balloons at first soared into the leaden gray skies above the city, wind and rain quickly sent thousands of them plunging into the bay, only blocks away.

"They were just dropping right out of the sky into the water," Fujita said.

Pictures of the balloons bobbing on the bay quickly made their way onto social media sites like Facebook and Flickr, as angry environmentalists blasted the stunt in e-mails and on Twitter.

"Obviously, we have a problem with polluting of the bay and this is just polluting and littering," said Amy Ricard, a spokeswoman for the environmental group Save the Bay.

"Your balloon campaign was a stupid thing to do to a city surrounded on three sides by water," one San Francisco resident said in an e-mail to GameStop. "You should be held accountable for the waste."

The companies quickly went to damage control.

"We understand the concerns consumers have regarding the impact balloons can have on the environment," read a statement released by GameStop. "However, the balloon drop stunt in San Francisco was created by THQ ... and Game-Stop had no prior knowledge of it."

A statement from THQ assured concerned bayside residents that the balloons released "were made from a 100% organic product and are 100% biodegradable," with no history of causing environmental pollution.

But just in case, the statement continued, "we've retained a clean up crew to remove any potential lingering debris."

Environmental groups remained concerned about potential danger to the bay and its sea life and the ocean.